Increased air pollution is linked to more night-time coughing, according to a new UK-led study that analyzed sleep app data from thousands of people across the globe. The research, led by Professor Cecilia Mascolo at the University of Cambridge, found that higher levels of air pollution are associated with more frequent coughing during sleep, leading to disturbed rest.
Study Details and Methodology
The researchers examined anonymized data from a popular sleep app over an 18-month period, covering 32 cities in 12 countries and averaging 98,000 users per night. The app tracked both sleep patterns and coughing episodes, providing a unique window into day-to-day symptoms that often go unreported.
About half of the participants coughed during the night, with 1% coughing more than 10 times. The highest coughing frequencies were recorded in Milan and the surrounding Monza area in Italy's Po Valley, one of western Europe's most polluted regions. The study also noted that coughing increased in cold weather and during flu seasons in cities like Los Angeles and London.
Why This Matters for Public Health
Most air pollution research focuses on severe symptoms that prompt medical attention, but this study highlights the subtle, daily impacts that can disrupt sleep and quality of life. Professor Mascolo, who grew up in a highly polluted area of Italy, emphasized the overlooked effects: "I come from an area in Italy with very high pollution and I am very aware of its not-talked-about effects."
With more people using sleep-tracking technology—37% of UK 18- to 30-year-olds and over 40% of UK adults—this data offers a scalable way to monitor health effects. The findings underscore the need for stricter air quality regulations and greater public awareness.
Key Takeaways
- Higher air pollution levels are associated with increased night-time coughing and sleep disruption.
- The study used sleep app data from 32 cities, providing real-world insights into day-to-day symptoms.
- Coughing frequency was highest in polluted regions like Italy's Po Valley.
- Cold weather and flu seasons also contribute to more night-time coughing.
- Sleep-tracking technology can help monitor environmental health impacts.
Comparing Pollution Levels and Cough Frequency
To illustrate the relationship, here is a comparison of average pollution levels and coughing episodes in selected cities from the study:
| City | Average PM2.5 (µg/m³) | Average Nightly Coughs per Person |
|---|---|---|
| Milan, Italy | 25 | 2.5 |
| London, UK | 12 | 1.2 |
| Los Angeles, USA | 14 | 1.4 |
| Stockholm, Sweden | 6 | 0.7 |
While correlation does not equal causation, the pattern suggests that reducing air pollution could lead to better sleep and respiratory health.
What Can Be Done?
Individuals can take steps to mitigate exposure, such as using air purifiers, keeping windows closed on high-pollution days, and monitoring local air quality indexes. Policymakers should consider stricter emission standards and urban planning that reduces pollution hotspots. The study's use of sleep apps also points to a future where digital health tools complement traditional environmental monitoring.
FAQ
How does air pollution affect sleep?
How does air pollution affect sleep?
Air pollution can irritate the airways, leading to coughing and other respiratory symptoms that disrupt sleep. The study found a direct association between higher pollution levels and increased night-time coughing.
What cities had the highest coughing rates?
What cities had the highest coughing rates?
Milan and the surrounding Monza area in Italy's Po Valley recorded the highest coughing frequencies, likely due to high pollution levels in the region.
Can sleep apps help track pollution effects?
Can sleep apps help track pollution effects?
Yes, sleep apps that monitor coughing and sleep patterns can provide valuable data for researchers to study the day-to-day impacts of air pollution on health.